1. Field of the Invention
The present invention relates to a network-based quality of experience (QoE) provisioning method for mobile video applications and an apparatus thereof.
2. Description of the Related Art
A QoE provisioning mechanism in the application level is recently being developed, in which a client application reports QoE-related information to an application server which adjusts media information, such as the quality of video, through a codec or rate adaptation.
A typical video transmission mechanism for supporting the dynamic video quality adjustment through application level signalling uses the following two methods.
The first is video streaming based on the real-time transport protocol/real-time streaming protocol (RTP/RTSP), which uses scalable video coding, such as video streaming-based H.294 and Dynamic Adaptive Streaming over hypertext transport protocol (HTTP) (DASH), and the second is HTTP-based video streaming for downloading small portions of a video with a specific video quality depending on the network status.
In RTP/RTSP-based video streaming, a video is transmitted together with a header including specific information for identifying the content of packets, after the video is coded. A base layer of the video is required for the basic quality in reproducing the video, and an enhancement layer of the video improves the video quality. If the enhancement layer is lost, the video quality may be affected, but the video can be continuously reproduced. If the base layer is lost, the video cannot be continuously reproduced.
In HTTP-based video streaming, the video is split into small portions with different qualities to be stored in the server. A client requests a portion of a specific video quality through an HTTP message, depending on the network congestion status. Accordingly, the video quality is dynamically adapted according to the current network congestion status.
FIG. 1 illustrates an application level QoE provisioning mechanism through an application function (AF), according to the prior art.
The AF, referred to as an application function, an application server, or a server in various embodiments of the present invention, is defined in the 3rd Generation Partnership Project (3GPP) for communication with an application server. If the application server can obtain more detailed information on the measured QoE, the application server requests an enhanced quality of service (QoS) for improving the QoE. Since this mechanism does not consider the current network status, an operator cannot sufficiently control through QoE provisioning.
The QoE of a video application relates to more factors than rate adaptation, such as application servers and a user's personal profiles. Therefore, a method for effectively improving the QoE using various factors as well as the network status is required.
In a video application through the Internet, while the QoE may be processed by the application, a service provider cannot control the traffic generated by an end user. However, in a mobile video application, the traffic can be controlled by network operators, such as QoE provisioning, flow-based charging, and application specific traffic treatment.
It is widely predicted that the video application will be a dominant future service in terms of the amount of consumed mobile data, rendering the video application process by the network in consideration of the QoE an important future consideration. Accordingly, there is a need in the art for a method by which an operator performs QoE provisioning for a video QoE provider and controls the network traffic.